1. Field of the Invention
The present invention relates to communication systems and to a system and method for implementing adaptive call admission control in such systems.
2. Description of the Related Art
A wireless communication system facilitates two-way communication between a plurality of subscriber units (fixed and portable) and a fixed network infrastructure. Exemplary communication systems include mobile cellular telephone systems, personal communication systems (“PCS”), and cordless telephones. An objective of these wireless communication systems is to provide communication channels on demand between the subscriber units and their respective base stations in order to connect a subscriber unit end user with the fixed network infrastructure (usually a wire-line system). In the wireless systems having multiple access schemes, a time “frame” is used as the basic information transmission unit. Each frame is sub-divided into a plurality of time slots. Subscriber units typically communicate with their respective base station using a “duplexing” scheme thus allowing for the exchange of information in both directions of the connection.
Transmissions from the base station to the subscriber units are commonly referred to as “downlink” transmissions. Transmissions from the subscriber units to the base station are commonly referred to as “uplink” transmissions. Depending upon the design criteria of a given system, wireless communication systems have typically used either time division duplexing (“TDD”) or frequency division duplexing (“FDD”) methods to facilitate the exchange of information between the base station and the subscriber units.